1. Field of the Invention
The present invention relates to a printer performing print by means of a printing head such as an ink-jet head onto a recording sheet of paper delivered from a recording paper roll housed in a roll paper housing. More particularly, the invention relates to a printer of a type in which replacement operation of a recording sheet roll is accomplished via an opening formed in the front surface of a roll paper housing.
2. Description of the Related Art
As a printer printing on a recording paper roll, there is known a type in which an opening/closing cover for replacing a recording paper roll is attached to the front surface of the printer, and when the cover is pulled down forward, the roll paper housing is exposed. Such a printer is disclosed, for example, in JP-A 3-258575. In the disclosed printer, a printing head is arranged downward above the roll paper housing, and a platen roller for regulating the printing position on the recording sheet is arranged opposite thereto. The recording sheet delivered from a recording paper roll housed in the roll paper housing is printed while passing on the printing position, and then, discharged outside from a paper discharge port formed above an opening for replacing the recording sheet in the front portion of the printer. In general, a cutter is attached near the paper discharge port to permit cutting of a tape-shaped recording sheet after printing automatically or manually.
The cover blocking the opening of the roll paper housing is locked by a locking mechanism at a closing position, so that, by releasing the lock, the cover falls down forwardly by a spring force to expose the roll paper housing. A platen roller which is a component part of the paper feed mechanism is attached on the cover side, to facilitate replacement of the recording sheet via the opening.
In a cover opening/closing mechanism in which parts composing the paper feed mechanism such as the platen roller are as well moved, together with the cover, the paper feed troubles may be caused unless the movable-side components of the paper feed mechanism returns to the original positions accurately in a closed state of the cover. Particularly when an ink-jet head is used as a printing head, the platen gap fluctuates, producing disadvantages such as a decrease in the print quality.
On the other hand, the printer using a recording paper roll is popularly applied as a receipt issuing printer at pay window of a kiosk or the like, and in such a case, the available space for installation is small in many cases. There is and has been therefore an increasing demand for development of a smaller-sized or more compact printer in this area of application. With this fact in view, it is desirable to configure a locking mechanism for locking the cover blocking the roll paper housing at the closed position thereof, and a mechanism for releasing the lock by the locking mechanism, into a compact shape without the need for a large space for installation.
In addition, it is always demanded to permit simple and safe opening/closing operation of the cover, and easy replacement of the recording paper roll.
An object of the present invention is therefore to provide a printer which carries out replacement of the recording paper roll by opening the cover attached to the front surface of the printer, which permits simple replacement operation of the recording paper roll.
Another object of the invention is to provide a printer which carries out replacement of the recording paper roll by opening the cover attached to the front surface of the printer, and causes movement of also some component parts of the paper feed mechanism transferring a recording sheet by a printing head via the printing position together with the cover, which permits accurate return of the moving parts, together with the cover, to the operating positions.
Still another object of the invention is to provide a printer which carries out replacement of the recording paper roll by opening the cover attached to the front surface of the printer, and causes movement of also some component parts of the paper feed mechanism transferring a recording sheet by a printing head via the printing position together with the cover, which permits accurate return of the moving parts, together with the cover, to the operating position, and ensures certain feed of recording sheets of paper without causing slip.
Further another object of the invention is to provide a printer which carries out replacement of the recording paper roll by opening the cover attached to the front surface of the printer, and in which a locking mechanism locking the cover at the closed position and a mechanism for releasing lock made by the locking mechanism are small and compact in size.
In addition, another object of the invention is to provide a printer which carries out replacement of the recording paper roll by opening the cover attached to the front surface of the printer, which permits simple and safe opening/closing operation of the cover.
To achieve the above and other objects, the printer of the present invention comprises a roll paper housing; a cover attached to the front surface of the printer for opening and closing the roll paper housing; a printing head for printing on a tape-shaped recording sheet of paper delivered from a recording paper roll charged in the roll paper housing; a paper feed mechanism for transferring the tape-shaped recording sheet through a printing position of the printing head; the paper feed mechanism comprising a fixed-side paper feed mechanism section and a movable-side paper feed mechanism section movable to an operating position and a shunting position distant from the fixed-side paper feed mechanism section, engaging with the fixed-side paper feed mechanism section; and the recording sheet being held between the fixed-side paper feed mechanism section and the movable-side paper feed mechanism section; and a parallel linking mechanism which causes the movable-side paper feed mechanism section to move to the operating position in linkage with the closing operation of the cover, and causes the movable-side paper feed mechanism section to move from the operating position to the shunting position while keeping the posture at the operating position, in linkage with the opening operation of the cover.
The aforementioned parallel linking mechanism may have a configuration in which the parallel linking mechanism has a pair of swinging arms; and the lower end of each swinging arm is rotatably supported by the roll paper housing side, and the upper end of each swinging arm is hinge-connected by the movable-side paper feed mechanism section.
The aforementioned paper feed mechanism may have a configuration in which the fixed-side paper feed mechanism section comprises a first roller and a second roller arranged in the upstream and in the downstream, respectively, of the printing head in the recording paper transferring direction; the movable-side paper feed mechanism section comprises a third roll in contact with the first roller and a fourth roller in contact with the second roller at the operating position; and the recording sheet is transferred between the first and third rollers, and between the second and fourth rollers.
In this case, the fixed-side paper feed mechanism section may have a configuration in which it further comprises a motor driving one of the first and second rollers, and a driven gear for transferring the driving force of the motor to the movable-side paper feed mechanism section. The movable-side paper feed mechanism section may further comprise a follower gear engaging with the driven gear at the operating position, and it suffices to derive one of the third and fourth rollers by driving force of the motor transferred to the follower gear.
Typically, the configuration may be such that the first and fourth rollers are driven by the motor. In this case, the movable-side paper feed mechanism section should preferably have a spring which presses the third roller against the first roller at the operating position.
It is desirable to adopt a configuration in which the second roller has a shape capable of being pressed with a slight contact portion against a recording sheet transferred between the second roller and the fourth roller, so as to rotate along with rotation of the fourth roller.
When the printing head is an ink-jet head or the like, the movable-side paper feed mechanism section should preferably comprise a roller supporting member rotatably supporting the third and fourth rollers, and a platen plate attached to the roller supporting member and arranged between the third and fourth rollers; and ends on one side of the pair of swinging arms should preferably be hinge-connected to the roller supporting member.
The printer of the invention comprises a roll paper housing; a cover attached to the front surface of the printer for opening and closing the roll paper housing; a printing head for printing on a tape-shaped recording sheet of paper delivered from a recording paper roll charged in the roll paper housing; a paper feed mechanism for transferring the tape-shaped recording sheet through a printing position of the printing head; the paper feed mechanism comprising a fixed-side paper feed mechanism section and a movable-side paper feed mechanism section movable to an operating position and a shunting position distant from the fixed-side paper feed mechanism section, engaging with the fixed-side paper feed mechanism section; and the recording sheet being held between the fixed-side paper feed mechanism section and the movable-side paper feed mechanism section; and a parallel linking mechanism which causes the movable-side paper feed mechanism section to move to the operating position in linkage with the closing operation of the cover, and causes the movable-side paper feed mechanism section to move from the operating position to the shunting position while keeping the posture at the operating position, in linkage with the opening operation of the cover; and further comprises an operating lever vertically rotatably attached to the movable-side paper feed mechanism section, and a locking mechanism for locking the movable-side paper feed mechanism section at the operating position; wherein, when the operating lever is turned, locking of the movable-side paper feed mechanism section by the locking mechanism is released.
In order to smoothly accomplish discharge of the printed recording sheets discharged by the paper feed mechanism, the operating lever should preferably have a guide table projecting from the movable-side paper feed mechanism section in front of the printer body; and, when the movable-side paper feed mechanism section is at the operating position, the recording sheet discharged between the movable-side paper feed mechanism section and the fixed-side paper feed mechanism section to outside is guided by the guide table.
The locking mechanism may comprise a vertically rotatable hook integrally with the operating lever, a hook receiver with which the hook is engaged from below, formed on the printer body side, and a spring imparting a force to the hook in a direction of engaging with the hook receiver.
Furthermore, the printer of the invention should preferably further comprise operating lever rotating means for vertically rotating the operating lever relative to the movable-side paper feed mechanism section in linkage with opening and closing of the cover.
In this case, the operating lever rotating means may comprise an engagement section formed on the operating lever at a position in front of the printer body from the rotation center of the operating lever, and an engaged section formed on the parallel linking mechanism; and the engagement section engages with the engaged section in linkage with the opening operation of the cover, and pushes up the operating lever around the rotation center so that the front side portion thereof moves upward. According to this configuration, the front portion of the operating lever attached to the cover is directed upward with the cover open, i.e., with the tilted cover. The operating lever can therefore be easily grasped, thus facilitating the closing operation of the open cover.
The aforementioned operating lever rotating means may comprise an engagement section formed on the operating lever at a position in front of the printer body from the rotation center of the operating lever, and an engaged section formed on the parallel linking mechanism; and the engagement section engages with the engaged section in linkage with the closing operation of the cover, and causes the operating lever around the rotation center so that the rear side portion moves downward, and when the operating position is reached by the movable-side paper feed mechanism section, engagement between the engagement section and the engaged section is released.
According to this configuration, it is possible to achieve a locked state of the cover by the locking mechanism by making use of the rotating motion of the operating lever, thus permitting easy locking operation of the cover at the closing position.
In a preferred embodiment, the portion of the paper feed mechanism on the recording sheet discharge side after printing is provided with a cutter for cutting the recording sheets. The cutter may comprise a movable edge and a fixed edge. The movable edge may be provided in the fixed-side paper feed mechanism section, and the fixed edge may be provided in the movable-side paper feed mechanism section. In this case, the operating lever should preferably have a protecting cover covering the front portion of the fixed edge so that the fixed edge exposed when the movable-side paper feed mechanism is at the shunting position never injure operator""s fingers or the like.
In another preferred embodiment, the printer should preferably further comprise a movable guide for guiding a recording sheet delivered from the recording sheet roll housed in the roll paper housing into the paper feed mechanism section; wherein the movable guide should preferably be attached to the movable-side paper feed mechanism section, and move in linkage with the operating lever.
More preferably, the movable guide rotates around the rotation center of the operating lever integrally therewith.
According to this configuration, when the movable-side paper feed mechanism is at the operating position, it is possible to move the movable guide without causing slip of the recording sheet so that the recording sheet is introduced into the paper feed mechanism from the transferring direction by the paper feed mechanism without fail. When the movable-side paper feed mechanism section moves to the shunting position, the movable guide can be moved so that the movable guide never hits the component parts of the fixed-side paper feed mechanism section.
In a preferred embodiment, the fixed-side paper feed mechanism section may have a first roller and a second roller arranged in the upstream and in the downstream, respectively, of the printing head in the recording sheet transferring direction; the movable-side paper feed mechanism section has a third roller in contact with the first roller and a fourth roller in contact with the second roller at the operating position; the recording sheet is transferred between the first and third rollers and between the second and fourth rollers.
When such a paper feed mechanism is used, there should preferably be provided a spring which presses the movable guide so as to be positioned on the first roller side relative to the contact positions of the first and third rollers, when the movable-side paper feed mechanism section is at the operating position. In this configuration, the winding angle onto the first roller of the recording sheet guided between the first and third rollers by the movable guide becomes larger. By using a driven roller as the first roller, therefore, it is possible to transfer the recording sheet accurately toward the printing position without the risk of occurrence of slip.
In order to detect whether or not the cover is closed, it suffices to arrange a guide detector for detecting the position of the movable guide. In order to detect whether or not the recording sheet delivered from the roll paper housing has been drawn out via the movable guide, it suffices to arrange a recording sheet detector for detecting whether or not there is a recording sheet on the movable guide when the movable-side paper feed mechanism section is at the operating position.
The printer of the invention comprises a roll paper housing; a cover attached to the front surface of the printer for opening and closing the roll paper housing; a printing head for printing on a tape-shaped recording sheet of paper delivered from a recording paper roll charged in the roll paper housing; a paper feed mechanism for transferring the tape-shaped recording sheet through a printing position of the printing head; the paper feed mechanism comprising a fixed-side paper feed mechanism section and a movable-side paper feed mechanism section movable to an operating position and a shunting position distant from the fixed-side paper feed mechanism section, engaging with the fixed-side paper feed mechanism section; and the recording sheet being held between the fixed-side paper feed mechanism section and the movable-side paper feed mechanism section; and a parallel linking mechanism which causes the movable-side paper feed mechanism section to move to the operating position in linkage with the closing operation of the cover, and causes the movable-side paper feed mechanism section to move from the operating position to the shunting position while keeping the posture at the operating position, in linkage with the opening operation of the cover. The roll paper housing has a roll holder supporting the recording sheet roll; at least a part of the roll holder is a holder moving section forwardly rotatable around the lower end thereof; and the holder moving section rotates forwardly in linkage with the opening operation of the cover.
The roll holder may comprise a bottom wall portion, a front wall portion opposite to the cover, a rear wall portion, and right and left side portions. In this case, the holder movable section suffices to contain at least the front wall portion.
The printer of the invention comprises a roll paper housing; a cover attached to the front surface of the printer for opening and closing the roll paper housing; a printing head for printing on a tape-shaped recording sheet of paper delivered from a recording paper roll charged in the roll paper housing; a paper feed mechanism for transferring the tape-shaped recording sheet through a printing position of the printing head; the paper feed mechanism comprising a fixed-side paper feed mechanism section and a movable-side paper feed mechanism section movable to an operating position and a shunting position distant from the fixed-side paper feed mechanism section, engaging with the fixed-side paper feed mechanism section; and the recording sheet being held between the fixed-side paper feed mechanism section and the movable-side paper feed mechanism section; and a parallel linking mechanism which causes the movable-side paper feed mechanism section to move to the operating position in linkage with the closing operation of the cover, and causes the movable-side paper feed mechanism section to move from the operating position to the shunting position while keeping the posture at the operating position, in linkage with the opening operation of the cover; wherein the lower end of the cover is rotatably supported on the roll paper housing side; and has a spring always pressing the cover against the parallel linking mechanism.